Alfred Kinsey, whose groundbreaking “Sexual Behavior in the Human Male” was published 50 years ago, based much of his “scientific research” on the experiences of a sole predatory pedophile, according to new evidence.

Mr. Kinsey, credited as the father of the sexual revolution whose statistics and research ushered in the age of sexual liberation, based a key section of his book about the behavior of children on the experiences of a man who had abused at least 800 boys and girls.

That man, an U.S. government land examiner now identified as Rex King, was given the code name “Mr. Green.” He was contacted by Mr. Kinsey after he had heard that Mr. King had recorded in explicit detail his catalogue of abuse in a series of diaries, which he had buried in the Arizona desert.

Mr. Kinsey’s reliance on this pedophile was disclosed a year ago with the publication of a biography. But the content of the diaries, recorded over a 20-year period, were disclosed for the first time in August on British TV in a program called “Secret History.” It reports that Mr. Kinsey’s chapter on the sexual behavior of children was based solely on Mr. King’s experiences, after the sexologist had convinced himself that they were “vital data.”

In 1948, Mr. Kinsey published large sections of “Mr. Green’s” diaries verbatim in his book but, rather than presenting them as the claims of a child abuser, he put them forward as the first scientific “proof” that children were sexual beings from birth.

In what scientists now say totally discredits much of Mr. Kinsey’s research, he published --with no independent corroboration --”Mr. Green’s” detailed descriptions of how he abused hundreds of children. “Mr. Green” lent his analysis a quasi-scientific bent by timing children’s reactions with a stopwatch.

Mr. Kinsey, who died in 1956, concluded that children could, with the assistance of an experienced adult, enjoy sexual activity from the moment they were born. This claim appalled his critics.

Judith Reisman, an academic, said: “We have a whole chapter in which children have been tortured for this so-called scientific data. This data suggests that a minimum of 317, and a maximum of 1,200 children [were abused], with some boys being sexually raped around the clock.”

New evidence also suggests that Mr. King was active with children until 1954, more than 11 years after he met Mr. Kinsey --during which time the sexologist continued to collect his “data” for his research.

“If Green was sexually abusing children until 1954 --and Kinsey’s last book came out in 1953 --that would certainly mean that all the violence and all the abuse was going on throughout the entire time Kinsey was collecting this data,” Miss Reisman said.

“Based on Kinsey’s writings, he approved fully of adult-child sexual interactions. Not only that, he recommended that adults could effectively aid their children in better sexual lives by giving them ‘orgasms’ at a very early age.”

Vincent Nowlis, one of Mr. Kinsey’s original team, has spoken for the first time about his disgust with the sexologist’s methodology. He said: “When I saw the table on timed orgasms . . . carried out to a fraction of second, I thought it was an absurd page in science.”

But Paul Gebhard, a senior member of Mr. Kinsey’s team, defended the use of “Mr. Green’s” accounts of his illegal activities, saying: “We knew it was illegal, but it’s very important for people to study childhood sexuality. Green . . . contributed a fair amount to our knowledge of sexuality in children.”

The current director of the Kinsey Institute, John Bancroft, believes Mr. Kinsey was morally justified.

He said, “Unless we know about these behaviors, we’ll be in a much worse position than if we have no information about them --that was Kinsey’s view.

“Kinsey didn’t ask anybody to carry out any particular form of sexual behavior. He simply asked them to let him know of their experiences.”

Dr. Adrian Rogers, the director of the Conservative Family Institute, described Mr. Kinsey’s research as unbelievable and unscientific, “yet it was given an almost sacrosanct authority.”

Victoria Gillick, a leading moral rights campaigner in Britain, said that Mr. Kinsey was the “first of the sexual freak shows.

“He was the excuse that was needed as justification for sexualizing the young, a process that has continued to this day.”